1. Field of the Invention
The present invention relates to constant velocity universal joints for connecting drive and driven members and, more particularly, the invention relates to universal joints embodying means of achieving constant velocity drive between the drive and driven members when the members are in high speed operation, offset at an angle, or have misalignment between the members. The apparatus achieves this with roller balls which are free to rotate in any direction. A multiplicity of such joints can be cascaded, or connected in series, to increase the degree of offset or misalignment that can be accomodated between the drive and driven members and/or the spacing therebetween. One embodiment of the system allows the ball joint to readily separate, thus making a quick positive disconnect.
2. Description of the Prior Art
Many efforts are shown in the known prior art to achieve better transmission of torque. These usually involve either a Cardan-type joint, such as shown in U.S. Pat. No. 4,156,354, or a constant velocity joint of the type shown in U.S. Pat. No. 2,910,845. Each of these devices involve transmission of torque between rotative members and can be said to involve an inner joint member fixed to one of the rotative members, and an outer joint member fixed to the other of the rotative members.
U.S. Pat. No. 4,156,354 shows a high-speed, high-torque transmitting joint where the torque is transmitted through roller bodies interposed between inner and outer joint members wherein the roller bodies are equidistantly spaced circumferentially of the joint assembly, with each roller body being received in planar recesses in the inner joint member for radially slidable engagement relative thereto. This construction increses the complexity and size of the joint, and requires close maintenance of surface finish and other manufacturing tolerances. Because of these reasons and the increased friction resulting from the sliding relationship of the planar surfaces, this type of joint has decreased smoothness of operation, while at the same time having increased manufacturing costs.
U.S. Pat. No. 2,910,845 shows a constant velocity universal joint intended for connecting two rotative members only where angularly misaligned joints are to be found, and not where axially aligned or slightly misaligned joints are to found and, therefore, shows a joint limited in its usefulness. Further, the joint utilizes spherical drive members restrained to rotate about journals provided on the drive member. The restraining of the drive members provides increased friction, which is unsatisfactory in a universal joint.
What is needed to solve the above problems present in the prior art is an improved constant velocity universal joint usable for angular and axial misalignment and having increased smoothness of operation due to the elimination of planar surfaces on the drive members and which can be made with lower manufacturing costs because of less critical tolerances and surface finishes.
In addition, increased friction results because of the sliding relationship of the planar surface. For these reasons, it provides a generally unsatisfactory solution to the problem of torque transmission.
U.S. Pat. No. 2,910,845 utilizes spherical drive members restrained to rotate about journals provided on the drive member which again causes increased friction and is unsatisfactory.